b) How many grams of strontium nitrate, Sr(NO3)2, are needed to prepare 3.40x10ʻmL of a 0.925 M solution?

Copper(II) sulfate, CuSO4, reacts with sodium hydroxide, NaOH, in a double displacement reaction. The products are a precipitate of copper (II) hydroxide, Cu(OH)2, and an aqueous solution of sodium sulfate, Na2SO4. CuSO4(aq) + 2NaOH(aq) → Cu(OH)2(s) + Na2SO4(aq) 50.0 mL of 0.300 mol/L CuSO4 solution are mixed with an equal volume of 0.600 mol/L NaOH. The initial temperature of both solutions is 21.4°C. After mixing the solutions in a calotimeter, the highest temperature reached is 24.6 oC. Determine the change in the enthalpy of the reaction. Then write the thermochemical equation.

The thermal conductivities of human tissues vary greatly. Fat and skin have conductivities of about 0.20 W/m · K and 0.020 W/m · K respectively, while other tissues inside the body have conductivities of about 0.50 W/m · K. Assume that between the core region of the body and the skin surface lies a skin layer of 1.0 mm, fat layer of 0.50 cm, and 3.2 cm of other tissues. (a) Find the R-factor for each of these layers, and the equivalent R-factor for all layers taken together, retaining two digits. Rskin m2 · K/W Rfat m2 · K/W Rtissue m2 · K/W R m2 · K/W (b) Find the rate of energy loss when the core temperature is 37°C and the exterior temperature is 0°C. Assume that both a protective layer of clothing and an insulating layer of unmoving air are absent, and a body area of 2.0 m2. W

For the chemical reaction   2HBr(aq)+Ba(OH)2(aq)⟶2H2O(l)+BaBr2(aq)2HBr(aq)+Ba(OH)2⁢(aq)⟶2⁢H2O(l)+BaBr2⁢(aq)   write the net ionic equation, including the phases.

Ethylene (CH₂CH₂) is the starting point for a wide array of industrial chemical syntheses. For example, worldwide about 8.0 × 10¹0 kg of polyethylene are made from ethylene each year, for use in everything from household plumbing to artificial joints. Natural sources of ethylene are entirely inadequate to meet world demand, so ethane (CH₂CH3) from natural gas is "cracked" in refineries at high temperature in a kinetically complex reaction that produces ethylene gas and hydrogen gas. Suppose an engineer studying ethane cracking fills a 35.0 L reaction tank with 35.0 atm of ethane gas and raises the temperature to 400. °C. He believes K₂=0.20 at this temperature. Calculate the percent by mass of ethylene the engineer expects to find in the equilibrium gas mixture. Round your answer to 2 significant digits. Note for advanced students: the engineer may be mistaken about the correct value of Kp and the mass percent of ethylene you calculate may not be what he actually observes.

Consider Copper (Cu), Silver (Ag), Silicon (Si), Aluminum oxide (Al2O3), silicon carbide (SiC), and polyvinyl chloride (PVC). Please select the correct answers. (There may be more than 1 correct answer!). (a) Cu and Ag are metal and have metallic bonding. Si, and Al2O3 are ceramic. PVC is polymer. (b) Cu, Ag and Si are metal. Cu and Ag have metallic bonding, but Si has covalent bonding.  SiC and Al2O3 are ceramic with covalent and ionic bonding, respectively. (c) Electrical conductivity: Ag > Cu > Si > Al2O3 > PVC (d) Cu and Ag have FCC structure. Si and SiC have diamond-type structure.

Archimedes tells us the lifting power of a balloon (how much mass it can lift) is equal to the difference between the mass of the balloon and the mass of the air it displaces. That is, if the balloon occupies the same volume as 10 kg of air, but the balloon only weighs 2 kg, then the gas density kg 0.090 3 m H, balloon can lift 8 kg. Airships have sometimes been filled with hydrogen (H,), but hydrogen is very flammable, and kg 0.18 Не m after the Hindenburg caught fire and crashed in 1937 with serious loss of life airships have nearly always been filled with helium (He) instead. kg 1.23 3 m' air Suppose a new airship Star of Balogna will have the shape of a cylinder 100. m long, with a radius of 15.0 m, and will weigh 9400. kg without any gas inside it. Suppose also the average passenger weighs 81 kg. Calculate how many passengers the Balogna could carry if it were filled with hydrogen, and also if it were filled with helium. Passengers with H,: Passengers with He:

What are the pH and pOH of 0.075 M NaOH(aq)?